drm/amd: check num of link levels when update pcie param

commit 406e8845 upstream.

In SR-IOV environment, the value of pcie_table->num_of_link_levels will
be 0, and num_of_levels - 1 will cause array index out of bounds

Signed-off-by: Lin.Cao <lincao12@amd.com>
Acked-by: Jingwen Chen <Jingwen.Chen2@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[ Resolve minor conflicts to fix CVE-2023-52812 ]
Signed-off-by: Bin Lan <bin.lan.cn@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>